https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80517
--- Comment #5 from Marc Glisse <glisse at gcc dot gnu.org> --- (In reply to Matthias Kretz from comment #3) > GCC 9 almost resolves this. However, for some reason this extended test case > is not fully optimized: https://gcc.godbolt.org/z/jRrHth > i.e. the call to dont_call_me() should be eliminated as dead code We are left with: _GLOBAL__sub_I__Z1fv () { <bb 2> [local count: 1073741824]: d = 125; return; } f () { unsigned int d.1_1; <bb 2> [local count: 1073741824]: d.1_1 = d; if (d.1_1 == 125) [...] This is a classic, if the initialization of global variables is only noticed to be constant after optimizations (as opposed to in the front-end), gcc doesn't manage to turn the dynamic initialization into a static one. Making the intrinsics constexpr may help, but really this is something that would be nice to fix eventually, there are several PRs blocked by this.
